Certain folk believe that they can assign to Life whatever meaning they
choose. That, in other words, value is arbitrary. I contend that this
is a circular belief system, and one imposed by evolution.

Let me define "circular belief". A circular belief system is one that
you hold because you hold it, and, if you *stopped* holding it, would
not pop up again. What atheists hate about religious beliefs is their
circularity. People are brought up to believe in God, to believe that
believing in God is Right, and that questioning their belief is wrong.
Many of these people, if they stopped believing that memeset, would have
no reason to start believing in God again. In other words, I'm talking
about the people who hold their religion out of a sheer refusal to think
about its absurdity, start over with a clean slate, and let the best
memetic system win. (I am not saying all religious people are like
this. After all, some born atheists convert to theism, blank-slate.)

The defining quality of circular religious systems is that they are
imposed on the mind to begin with, by culture or evolution, and that if
the imposed starting postulate is abandoned, they stop being plausible.

John K Clark wants to explore the galaxy, because it's "fun". He thinks
this makes exploring the galaxy meaningful. Suppose I abandon the
postulate that pleasure is valuable. Is there any way to get back to
this postulate again?

Evolution says: Pleasurable things are valuable by default. This
almost, but not quite, is the definition of pleasure - since many belief
systems say that all sorts of pleasurable things are anti-valuable.

So that's the seed of the circular belief system.
Now abandon the idea that pleasurable things are valuable.
Now, without accepting it as a postulate, prove it.

If you can't do this, it's a circular belief system, and one which I -
denying the basic postulate, just as John K Clark denies the existence
of God - have no reason to accept, until somebody comes out with some
kind of rational reasoning in favor of the basic postulate.

Moreover, I'd like to remind everyone that this issue doesn't seem at
all Euclid-arbitrary to me. It's not a matter of: Some accept this
postulate, some don't. At worst it's Godel undecidable, which means
that you can accept either postulate and be consistent, but one of them
is untrue to the extent of forcing a new definition of "number". But I
think that the basic postulate - "meaning is arbitrary" - is simply
WRONG, and what I want everyone to accept is that anybody who starts out
with this postulate is simply WRONG until they justify it.

If I say: "The Meaning of Life is pleasure" or "The Interim Meaning of
Life is Singularity", I can *justify* it. I can argue it to somebody
who doesn't start out believing it. Rightly or wrongly isn't the issue;
the point is that neither are basic postulates built into the system.

"The Meaning of Life is arbitrary."
"Whatever is fun to Observer X, is meaningful."
Well, I don't believe it yet.
How do I reason to it without accepting it as given?